Output parser bugs fixed; error messages improved

Changes since langchain-core==1.4.8

release(core): 1.4.9 (#38728) fix(core): improve langsmith loader error messages (#35648) fix(core): output parser bugs in xml.py and pydantic.py (#35641) style(core): fix some ruff preview rules (#38656) fix(core): avoid dict shadowing in language models (#38480) fix(core): _parse_google_docstring mishandling continuation lines with colons (#35680) fix(core): add messages to bare raise ValueError calls (#38158) fix(core): use asyncio.get_running_loop() in async contexts (#38157) chore: bump langsmith from 0.8.0 to 0.8.18 in /libs/core (#38319) chore: bump jupyterlab from 4.5.7 to 4.5.9 in /libs/core (#38326) chore: bump vcrpy from 8.1.1 to 8.2.1 in /libs/core (#38327)